Project Blue Book Case #1052. On February 11, 1952, a bright object was observed over Pittsburgh, Pennsylvania — America's steel capital and one of the most important industrial cities in the country. Pittsburgh's steel mills, coke plants, and heavy industry were vital to national defense, producing the raw materials for everything from warships to tanks.
Pittsburgh's position at the confluence of the Allegheny, Monongahela, and Ohio rivers created a dramatic topography of hills, valleys, and bridges. Greater Pittsburgh International Airport and the Allegheny County Airport handled the city's air traffic. The region's industrial haze was legendary in 1952, though clear winter nights could provide excellent observation conditions above the valley fog.
February 1952 was early in the wave's buildup. The case was classified "Unknown."